Symbolic analysis detects alterations of cardiac autonomic modulation in congestive heart failure rats

Congestive heart failure (CHF) is associated with neurohumoral activation. Only very few studies have examined the progression of autonomic dysfunction in CHF in humans and scanty data are available in animal models of CHF. This study was performed to assess the changes in cardiac autonomic modulation during the progression of CHF in a rat model, using an innovative analysis of heart rate variability. Progression of cardiovascular autonomic dysfunction was assessed in a rat model of CHF induced by coronary artery ligation. Spectral and symbolic analyses were performed on heart period (approximated with pulse interval, PI) and systolic arterial pressure (SAP) signals, acquired ~ 2 and ~ 4 weeks after the surgical procedure. As CHF developed, symbolic analysis revealed a decrease of rhythmical physiological sympathetic modulation, as indicated by the reduction of the percentage of stable patterns. In addition, symbolic analysis revealed that runs of short–long–short and/or long–short–long PI values and high–low–high and/or low–high–low SAP values were more and more frequent as CHF progressed. On the contrary, spectral analysis of PI and SAP series was not able to detect any impairment of autonomic regulation. Indeed, low frequency and high frequency powers derived from both PI and SAP series were not significantly changed. These data indicate that the autonomic cardiovascular modulation is altered during the progression of CHF and that symbolic analysis seems to be more suitable than spectral analysis to describe alterations of heart period dynamics and of cardiovascular regulation in this animal model of CHF.     

Evaluation of antimicrobial activity antiseptics and disinfectants used in a public health service

The study aimed to determine the in vitro antimicrobial activity of antiseptics and disinfectant used in the care service primary health of a city in northern Paraná, using microorganisms standardized by the National Institute of Quality Control in Health, Oswaldo Cruz Foundation. For this purpose, we performed tests of antimicrobial activity and chemical stability of three samples of antiseptic and one disinfectant used in the service. From the analysis performed the first, seventh, fourteenth and twenty-first day after the opening of the bottles, it was found that the samples retained their activity in vitro antimicrobial regarding standardized strains, as evidenced by the absence of growth of colony-forming units and maintaining the chemical stability. The study demonstrated the efficacy of the samples against analysis microbiological in vitro using standardized microorganisms.